Article about bridge agraffes - function, types

[Calin Tantareanu]

I have seen this sometimes done by harpsichord makers who put a thicker wire
next to the bridge pins and let the strings bear on it, not directly on the
wood.
The effect is that the footprint of a string is increased, the termination
stiffness somewhat too, although not as much as with a proper agraffe.

Why would they do this if not to improve the sound? In the ones I've seen I
had the impression that it contributed to a better sustain and livelier
sound.

Calin Tantareanu
http://calin.haos.ro
--------------------

> -----Original Message-----
> From: pianotech-bounces at ptg.org 
> [mailto:pianotech-bounces at ptg.org] On Behalf Of RicB
> Sent: luni, 20 noiembrie 2006 22:45
> To: pianotech at ptg.org
> Subject: Article about bridge agraffes - function, types
> 
> Hi again Calin, others
> 
> I just had a thought about how you might find out whether an 
> increase in 
> termination stiffness alone could account for any significant 
> change in 
> sustain and efficiency in general. You could lay a couple centerpins 
> under the strings on the bridge cap tight up against the 
> bridge pins.  
> They would have to be sunk into the wood so as to not really change 
> downbearing more then a hair... but you'd have your increase in 
> stiffness with a minimal of mass increase. 
> 
> Just a thought.
> 
> RicB
> 
> 
> 
>      > I think you may be missing the point. You gave a weight of
>      > 18.2 gr each for Steingraeber agraffes, of which the
>      > accompanying photo shows 16 in the top treble section. The
>      > agraffes weigh in at 291 gr all by themselves in that section
>      > alone, which is around twice the mass load I'd typically
>      > install in a conventional bridge in that section. The Stuart,
>      > etc, aren't that heavy, but still add up to a significant
>      > mass, which is the reason for the increased sustain, not the
>      > termination quality. Having listened to sustain times before
>      > and after the addition of mass to treble bridges with no
>      > changes to the pinning, I can assure you that mass can rather
>      > dramatically extend sustain times.
> 
>     Interesting. I can't tell how much of the improved sustain is
>     because of the
>     added mass and how much because of the improved 
> termination quality
>     of the
>     agraffe.
>